New Infiniti hybrid to get standard audible pedestrian warning system

The model, which goes on sale in six months' time, responds to concerns that pedestrians and other road users can't hear hybrid vehicles through the inclusion of an audible pedestrian warning system as standard.

The Infiniti new Approaching Vehicle Sound for Pedestrians (VSP) technology is computer-controlled and links an in-car sound synthesiser with a speaker built in to the front bumper. It automatically works from start-up to 30km/h, cutting back in at 25km/h as the vehicle slows.

Infiniti says that, rather than using a single tone, it opted for a range of high-low sounds at different volume levels after an extensive research programme to find the most effective, but least intrusive, noise. The result is a sine-wave sound that extends from 2.5kHz at the high end to a low of 600Hz. It is a range readily audible to all age groups while avoiding a sound range (around 1,000Hz) that would add unnecessary noise to the environment.

The noise sweeps from high to low frequency depending on vehicle speed and whether the M35h is accelerating or decelerating. It is loudest at start-up to give a clear indication the vehicle is beginning to move off, while an intermittent tone is used when reversing to help ensure the M35h cannot surprise pedestrians and the visually impaired as it approaches.

The AVS system will come ready installed on every M35h in Europe when sales commence from spring 2011 (depending on country).